Frequency of triploids in different interploidal crosses of citrus

The frequency of triploids in progenies from 2× × 4× and 4× × 2× crosses of Kinnow mandarin and Succari sweet orange was analysed. Chromosome counts indicated that crosses among tetraploid × diploid Kinnow yielded maximum triploids while reciprocal crosses of Kinnow exhibited a mixed population of diploid, triploid and tetraploid seedlings. The occurrence of triploids varied from 25% to 83.4% depending on the pistillate parents used. Crosses of diploid Succari with tetraploid Kinnow also produced nucellar diploid, sexual triploid and tetraploid seedlings. The highest number of tetraploids (71.4%) were produced in cross of tetraploid Kinnow with diploid Succari.